Benefits Plans (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended
	Jun. 30, 2013 Pension Plans, Defined Benefit	Jul. 01, 2012 Pension Plans, Defined Benefit	Jun. 30, 2013 Pension Plans, Defined Benefit	Jul. 01, 2012 Pension Plans, Defined Benefit	Jun. 30, 2013 Other Postretirement Benefit Plans, Defined Benefit	Jul. 01, 2012 Other Postretirement Benefit Plans, Defined Benefit	Jun. 30, 2013 Other Postretirement Benefit Plans, Defined Benefit	Jul. 01, 2012 Other Postretirement Benefit Plans, Defined Benefit	Dec. 31, 2012 CAS/PPA Harmonization Rules [Member] Pension Plans, Defined Benefit
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 80	$ 71	$ 160	$ 142	$ 4	$ 3	$ 8	$ 6
Interest cost	124	131	248	262	13	14	26	28
Expected return on plan assets	(148)	(147)	(296)	(294)	(7)	(8)	(14)	(15)
Recognized net actuarial loss	106	66	212	132	6	3	12	5
Amortization of prior service (credit) cost	(15)	(11)	(30)	(22)	2	2	4	4
Net periodic cost	147	110	294	220	18	14	36	28
Requests for CAS equitable adjustment									$ 165